The reason Apple needs a music streaming service explained in one chart

Apple revealed its new music streaming app, Apple Music, at its annual developers conference on Monday. Apple Music will let you stream "millions and millions" of songs from iTunes, alongside curated playlists and music videos. The app also comes with a 24/7 radio service called Beats 1, and Connect, a social platform where artists can share back stage photos or new track materials with their fans.

Today's announcement comes at an interesting time for Apple's music business. According to data from Bank of America, charted for us by BI Intelligence, music download revenue from Apple's music store has been in a steady decline over the past three years. In 2012 and early 2013, music downloads accounted for as much as 88% of Apple's revenue from its online music store - but in the second quarter of 2015, it's down to 62% of total revenue.

"We attribute a part of this decline in music downloads to the growing popularity of streaming audio," Bank of America wrote in a report.

It remains to be seen how Apple Music will do in the market. But Apple is marketing it aggressively — the first three months of the service will be offered for free once it launches on June 30. After the first three months, it will cost $9.99 a month, or $14.99 a month for a family package of up to six people.